1. Field of the Invention
The present invention belongs to a technical field of an insulation displacement connector having contacts for connecting cores of electric wires by insulation displacement. Particularly, the present invention relates to an insulation displacement connector in which an operation type locking mechanism to be engaged with a partner connector is provided in an outer wall of a connector housing.
2. Description of the Related Art
Conventionally, a crimp style connector having contacts for crimping cores of electric wires has been used widely. As such a crimp style connector, there is known a connector having an operation type locking mechanism provided in an outer wall of a connector housing so as to be engaged with a partner connector (for example, see Japanese Patent No. 3009653). The locking mechanism includes a support portion and an arm. The support portion is formed to protrude outward from the outer wall of the connector housing, and the arm has an engaging portion provided at a front end and shaped like a hook curved toward the outer wall, a gripping portion provided at a rear end, and an intermediate portion connected to the support portion. When the crimp style connector including the locking mechanism is connected to the partner connector, the engaging portion of the arm of the locking mechanism is engaged with an engaged portion of the partner connector so that the two connectors are connected to each other strongly. Hence, even in the case where the crimp style connector suffers draw-out force from the electric wires, the crimp style connector is hardly drawn out from the partner connector. Hence, connection failure can be prevented from occurring. When the gripping portion is pressed, the engagement is released so that the crimp style connector can be removed from the partner connector easily.
The operation of crimping electric wires to the crimp style connector is carried out by the steps of: overlapping cores of front ends of electric wires with end potions of contacts respectively; crimping the cores with barrels respectively while plastically deforming the barrels by a crimping tool; and inserting the contacts including the electric wire one by one into cavities of the connector housing. Hence, a large number of steps are required, so that the manufacturing cost becomes high. Moreover, it is difficult to shorten the required time for delivery of such connectors including electric wires, and this problem becomes remarkable in a multi-pole connector in which one connector has a large number of contacts. In this respect, an insulation displacement connector having contacts for insulation displacement of cores of electric wires is resolutely advantageous. The insulation displacement connector can achieve reduction in the manufacturing cost and shortening the required time for delivery of such a connector including an electric wire regardless of the number of poles. This is because insulation displacement of electric wires to the insulation displacement connector is performed by pressing all electric wires simultaneously into slots of contacts by an insulation displacement machine in the condition that all the contacts are inserted into the cavities of the connector housing. Generally, the insulation displacement machine has an insulation displacement stand for supporting the insulation displacement connector, and a movable unit which moves back and forth relative to the insulation displacement stand. Electric wire insertion holes communicating with the slots of the contacts are opened in one outer wall of the connector housing of the insulation displacement connector. The other outer wall opposite to the one outer wall is provided as a pressure-receiving wall so that an insulation displacement load is received by the pressure-receiving wall. The insulation displacement connector is set in the insulation displacement machine so that the pressure-receiving wall comes into contact with the insulation displacement stand. The electric wires are positioned on the electric wire insertion holes and pressed by a punch mounted in the movable unit so that the electric wires are forced into the slots. In this manner, insulation displacement is performed simultaneously.
If the aforementioned locking mechanism is provided in the insulation displacement connector, reduction in the manufacturing cost and shortening in the required time for delivery of such a connector including an electric wire, which are advantages of the insulation displacement connector, can be achieved while connection failure due to the locking mechanism is prevented from occurring between the connector and a partner connector. In such a case, however, the locking mechanism is provided in the pressure-receiving wall in the condition that the locking mechanism does not disturb insertion of the electric wires into the electric wire insertion holes. If so, the pressure-receiving wall cannot come into surface contact with the insulation displacement stand of the insulation displacement machine because of interference of the locking mechanism. Hence, the load for insulation displacement cannot be received by the insulation displacement connector steadily, so that the electric wires cannot be connected with the connector by the insulation displacement machine. Particularly in a multi-pole connector, this problem becomes serious because the load for insulation displacement becomes large. For this reason, there is no insulation displacement connector including a locking mechanism which has been put into practical use.
In such a multi-pole connector, when one end side of a contact raw receives stronger draw-out force than the draw-out force acting on the other end side in the condition that draw-out force from the electric wires acts on the connector, the connector is inclined to the partner connector. Hence, the one end side is floated up from the partner connector, and there is therefore a problem that contact failure occurs between the one-end side contact and the partner contact. Particularly such a connector including a locking mechanism is apt to face such a problem because the connector is often used in the condition that intensive draw-out force acts on the connector. It is also preferable from the point of view of preventing connection failure that a sense of completion of connection (hereinafter referred to as clicking sense) is obtained intensively when the connector is connected to the partner connector.
The present invention is designed upon such circumstances and an object of the present invention is to provide an insulation displacement connector provided with a locking mechanism in which: a portion of a connector housing for receiving slots of contacts is shifted to the longitudinal direction of the contacts more than a locking mechanism so that a pressure-receiving wall for receiving a load for an insulation displacement is secured to make it possible to connect electric wires with an insulation displacement machine; and the fitting length of the contacts is kept sufficient so that connection failure can be prevented and an intensive clicking sense can be obtained even in the case where the insulation displacement connector suffers draw-out force from the electric wires.
In order to achieve the above object, the insulation displacement connector according to a first aspect of the invention has a feature that the insulation displacement connector comprises: male or female contacts each having a connection portion and slots, the connection portion being provided at a front end and being brought into contact with a partner contact on an assumption that a lengthwise direction is regarded as a front-rear direction, the slots being opened toward one heightwise direction perpendicular to the front-rear direction with insulation displacement and being provided in a side more rear than the connection portion for fitting a core at a front end of an electric wire inserted from the one heightwise direction; a connector housing having cavities, the cavities being formed so as to pierce the connector housing in the front-rear direction and for receiving the contacts; a holding mechanism for holding the contacts in the connector housing; a support portion formed so as to protrude outward from an outer wall at one of ends, in the heightwise direction, of the connector housing; and an arm extending in the front-rear direction and having an intermediate portion or a rear end connected to the support portion and having an engaging portion provided at a front end of the arm so that the engaging portion engages with the partner connector; wherein a connector housing rear half portion of the connector housing for receiving the slots of the contacts is provided in a side more rear than the support portion and the arm; wherein electric wire insertion holes communicating respectively with the slots are opened in one outer wall located at the one end, in the heightwise direction, of the connector housing rear half portion; and wherein a portion, corresponding to the slots, of the other outer wall opposite to the one outer wall is provided as a pressure-receiving wall for receiving an insulation displacement load.
In the insulation displacement connector, the connector housing rear half portion is located at the side more rear than the support portion and the arm. Hence, electric wire insertion holes are opened in one outer wall located at one end, in the heightwise direction, of the connector housing rear half portion. Moreover, a portion, corresponding to the slots, of the other outer wall opposite to the one outer wall is provided as a pressure-receiving wall. Even in this case, the pressure-receiving wall can come into surface contact with the insulation displacement stand of the insulation displacement machine without being interfered by the locking mechanism. Hence, the insulation displacement load can be received by the insulation displacement wall steadily regardless of the number of poles, so that the electric wires can be fit by the insulation displacement machine. That is, if the insulation displacement connector is set in the insulation displacement machine in the condition that the pressure-receiving wall of the connector housing rear half portion comes into contact with the insulation displacement stand, and if front ends of the electric wires are then positioned respectively on the electric wire insertion holes and pressed by a punch so that the electric wires are forced into the slots, simultaneous insulation displacement can be performed. Hence, the insulation displacement connector including the locking mechanism can achieve reduction in machining cost and shortening in the time of delivery of the connector including electric wires because the insulation displacement connector is supposed to be superior in this respect to a crimp style connector.
When the insulation displacement connector is connected to the partner connector, the engaging portion of the arm of the locking mechanism is engaged with the engaged portion of the partner connector so that the two connectors are connected to each other strongly. Hence, even in the case where the insulation displacement connector suffers draw-out force from the electric wires, the insulation displacement connector is hardly drawn out from the partner connector to thereby prevent connection failure from occurring. When the gripping portion is then pushed, the fitting is released so that the insulation displacement connector can be removed from the partner connector easily.
Moreover, the connector housing rear half portion for receiving the slots of the contacts is provided on the side more rear than the support portion and the arm. Front ends of cores of the electric wires are positioned on the rear side correspondingly, so that the connection portion of each contact can be set longer. Hence, the fitting length of the contact can be set longer. Even in the case where the insulation displacement connector suffers draw-out force from the electric wires, connection failure caused by inclination of the insulation displacement connector or the like can be prevented and an intensive clicking sense can be obtained.
The insulation displacement connector according to a second aspect of the invention has a feature that in the configuration stated in the first aspect of the invention, the pressure-receiving wall is formed to be in a solid state.
In such a manner, the strength of the pressure-receiving wall is improved. Hence, the insulation displacement load acting on the contacts is received by the pressure-receiving wall steadily and transmitted to the insulation displacement stand securely. Hence, the electric wires can be fit more steadily by the insulation displacement machine.
The insulation displacement connector according to a third aspect of the invention has a feature that in the configuration stated in the first or second aspect of the invention, the engaging portion is shaped like a hook curved toward the outer wall portion of the connector housing, an engaged portion is provided in an outer wall of the partner connector so that the hook-like engaging portion is grappled with the engaged portion, and the arm has the intermediate portion connected to the support portion and has a gripping portion provided at a rear end.
In such a manner, when the insulation displacement connector is connected to the partner connector, the engaging portion of the arm in the locking mechanism rides over a surface of the engaged portion of the partner connector in the farther side from the connector housing and is then engaged with the engaged portion so that the two connectors are coupled to each other. When the gripping portion is then pressed toward the connector housing, the fitting is released so that the insulation displacement connector is removed from the partner connector. Such a locking mechanism which locks the connector housing of the partner connector from its outside is called an outer lock type.
The insulation displacement connector according to a fourth aspect of the invention has a feature that in the configuration stated in the first or second aspect of the invention, the engaging portion is shaped like a hook curved so as to depart from an outer wall portion of the connector housing, and an engaged portion is provided in the outer wall of the partner connector so that the hook-like engaging portion is grappled with the engaged portion.
In such a manner, when the insulation displacement connector including the locking mechanism is connected to the partner connector, the engaging portion of the arm in the locking mechanism rides over a surface of the engaged portion of the partner connector in the nearer side to the connector housing and is then engaged with the engaged portion so that the two connectors are coupled to each other. When the intermediate portion of the arm is then pressed toward the connector housing, the fitting is released so that the insulation displacement connector is removed from the partner connector. Such a locking mechanism which enters the inside of the connector housing of the partner connector is called an inner lock type.
The insulation displacement connector according to a fifth aspect of the invention, has a feature that in the configuration stated in any one of the first to fourth aspects of the invention, the holding mechanism is a contact lance mechanism or a housing lance mechanism.
In such a manner, the contact lance mechanism or housing lance mechanism is higher in holding force than the press-in mechanism. Hence, the contacts are hardly removed from the connector housing even in the case where the contacts suffer draw-out force from the electric wires.
The insulation displacement connector according to a sixth aspect of the invention has a feature that in the configuration stated any one of the first to fifth aspects of the invention, the holding mechanism further has a press-in mechanism.
If the contact lance mechanism or housing lance mechanism is rickety, there is a possibility that the position of each slot may be displaced from its regular position when the insulation displacement connector is set in the insulation displacement machine. On this occasion, the electric wires cannot be fit well. However, according to the sixth aspect of the invention, the position of each contact in the connector housing is settled before insulation displacement. Accordingly, when the insulation displacement connector is set in the insulation displacement machine, any slot is not displaced and the electric wires can be fit to the insulation displacement connector securely by the insulation displacement machine.